Optical disk apparatus

ABSTRACT

In an optical disk apparatus, when the write-in process to the optical disk is interrupted, a data processing part and an encoder part are set to be in the waiting state after an access to a data storing part is completed, so as to stop accessing the data storing part and also to stop storing data that is to be written. Thus, the interleave can be managed and the DSV calculation can be properly conducted without any irregular calculation. Even in a case in which the write-in process to the optical disk is restarted after temporarily interrupted, it is possible to read data similar to a case in which data to be written is successively written without an interruption.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an optical disk apparatus forrecording and reproducing information to and from a optical disk capableof recording data such as a CD-R/RW, DVD−R/RW, DVD+RW, or a like.

2. Description of the Related Art

Conventionally, it is required to complete writing data to be recordedto the optical disk capable of recording data such as a CD-R/RW,DVD−R/RW, DVD+RW, or a like, at once. Such a conventional once writingoperation is called “Track at Once” or “Disc at Once”. During theconventional once writing operation, in a case in which a writing speedis faster than a data transmission speed from a host computer and datato be written to the optical disk is interrupted, that is, in a case inwhich a buffer under-run occurs, it ends up failing to write data to theoptical disk.

The faster a data write operation is conducted, the more the bufferunder-run occurs. Especially for a medium that is not re-writable suchas a CD-R, an occurrence of the buffer under-run is a fatal error.Conventionally, in a method for avoiding the buffer under-run, acapacity of a buffer RAM (Random Access Memory) (for example, a memoryconsisting of a DRAM (Dynamic Random Access Memory)) is increased or aspeed of writing data to the optical disk is set to be slower than thatof transmitting data from the host computer.

Japanese Laid-Open Patent Application No.10-49990 discloses that insteadof avoiding the buffer under-run, the data write operation istemporarily interrupted when the buffer under-run occurs, the data writeoperation is resumed from an interrupted location on the optical diskafter a sufficient amount of data is transferred from the host computerand accumulated in the buffer RAM. Accordingly, during the data writeoperation to the optical disk, even when the fatal buffer under-run thatis a fatal error occurs, it is possible to complete writing dataproperly to the optical disk without a failure of writing data.

However, in a recording control as disclosed in the Japanese Laid-OpenPatent Application No.10-49990, a data recording operation to theoptical disk may be frequently stopped and resumed. Generally, datatransferred from the host computer is temporarily maintained in thebuffer RAM and a predetermined parity code is encoded and additionallyprovided in the data. After that, a CIRC process, an EFM (Eight toFourteen bit Modulation) encoding process, or a like is conducted forthe data and the data is recorded as record data on the optical disk.Recently, in a general optical apparatus, a capacity of the buffer RAMis approximately 512 Kbytes to 8 Mbytes.

For example, a recording speed of a CD is 150 Kbytes/sec at standardspeed. In correspondence to a recent improvement of the recording speed,the recording speed of the CD becomes 2.4 Mbytes/sec at 16-times speedrecord. Thus, a recording time for recording the data temporarilymaintained in the buffer RAM is relatively limited. That is, it isrequired to transfer new data during the recording time. Otherwise, thebuffer under-run occurs and the recording operation is temporarilystopped. Even though performance of host computer connected to theoptical disk apparatus is improved, in order to secure a stableoperation for any host computer, it is required for the optical disk toconduct an operation for a case in which the recording operation istemporarily stopped and resumed frequently.

However, under a circumstance in which the recording operation isfrequently stopped and resumed, when an end location previously recordedis detected and it is controlled to resume recording precisely from theend location, a displacement amount between absolute locationinformation and a location where data is recorded on the optical disk isaccumulated. In this case, when the displacement amount exceeds aconstant value, the recording operation cannot be resumed. That is, asdescribed above, a data amount capable of maintaining data transferredfrom the host computer at once is limited to a maximum capacity of thebuffer RAM. Thus, it is required to temporarily stop the recordingoperation if data is not transferred from the host computer again beforethe optical disk apparatus completes recording data accumulated in thebuffer RAM. The smaller the capacity of the buffer RAM, or the fasterthe recording speed for recording data to the optical disk, the morefrequently the buffer under-run occurs.

SUMMARY OF THE INVENTION

It is a general object of the present invention to provide an opticaldisk apparatus in which the above-mentioned problems are eliminated.

A more specific object of the present invention is to provide theoptical disk apparatus in which even if a write-in process is restartedfrom an interrupted location on an optical disk after the write-inprocess is temporarily interrupted while writing data on the opticaldisk, data written on the optical disk can be read successively andnormally as the same as a single write-in process is conducted.

The above objects of the present invention are achieved by an opticaldisk apparatus for recording and reproducing information to an opticaldisk capable of recording data in which address information indicating alocation of blank area, the optical disk apparatus including: a datastoring part temporarily storing data externally transferred to bewritten on the optical disk for conducting a predetermined data process;a data processing part for conducting the data process for the datastored in the data storing part; an encoding part demodulating andoutputting the data processed by the data processing part to be written;a write-in controlling part conducting a operation control of the dataprocessing part and the encoding part and conducting a storing controlof storing the data to be written to the storing part; and a write-inoperation instruction part detecting a state of interrupting supplyingthe data to be written to the data storing part, and conducting anoperation instruction to the write-in controlling part in accordancewith a detection result; wherein when the write-in controlling partinterrupts writing data to the optical disk, the write-in controllingpart sets the data processing part and the encoding part to be in awaiting state after an access to the data storing part is completed, sothat the access to the data storing part is stopped and the data to bewritten is stopped to store in the data storing part.

According to the present invention, the interleave can be managed andthe DSV calculation can be properly conducted without any irregularcalculation. Even in a case the write-in process to the optical disk isrestarted after temporarily interrupted, it is possible to read datasimilar to a case in which data to be written is successively writtenwithout an interruption.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, embodiments of the present invention will be describedwith reference to the accompanying drawings.

FIG. 1 is a schematic block diagram showing a configuration example ofan optical disk apparatus according to the present invention;

FIG. 2 is a diagram showing a format of a write-in unit for writing dataon a CD-R/RW, which is specified in an Orange Book;

FIG. 3 is a diagram showing a format example of a case in which the userdata block shown in FIG. 2 is divided into several user data blocks whenrecorded on the optical disk;

FIG. 4 is a schematic block diagram showing a configuration example ofthe CD encoder;

FIG. 5 is a flowchart for explaining the write control operation exampleconducted in the optical disk apparatus 1 shown in FIG. 1 and FIG. 4;

FIG. 6 is a diagram showing a relationship between an end locationindicating an end writing data and a start location indicating a startwriting data on the optical disk , which is specified by the OrangeBook;

FIG. 7 is a diagram showing an example of data connection on the opticaldisk.

FIG. 8 is a diagram showing a relationship between the sub-code SYNC andthe frame SYNC on the optical disk and the sub-code SYNC and the frameSYNC after demodulated;

FIG. 9 is a diagram showing a relationship of the ATIP SYNC afterdemodulated;

FIG. 10 is a diagram showing a state example of data connection on theoptical disk; and

FIG. 11 is a diagram showing an example of an EFM data recorded on theoptical disk.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment according to the present invention will now be describedwith reference to figures.

FIG. 1 is a schematic block diagram showing a configuration example ofan optical disk apparatus according to the present invention. In FIG. 1,a CD-R is exampled. For the sake of convenience, a SYNC pattern iscalled SYNC.

In the optical disk apparatus of FIG. 1, an optical pickup 3 conducts adata read operation and a data write operation to an optical disk 2 andincludes a semiconductor laser, an optical system, a focus actuator, atrack actuator, a photo detector, a position sensor, and a like (notshown).

A data signal read by the optical pickup 3 is amplified by a readamplifier 4 to convert into binary data. In order to decode the binarydata into decoded data, a CD decoder 5 conducts an EFM modulation and aCIRC calculation (a de-interleave, an error correction, or a like) forthe binary data amplified by the read amplifier 4. When the decoded datais used as audio data (hereinafter, called CD data), the D/A (digital toanalogue) converter 6 conducts a D/A conversion and outputs the decodeddata as an audio signal.

Also, the CD decoder 5 outputs the decoded data that is the CD data ordata for a personal computer (hereinafter, called CD-ROM data), to aCD-ROM decoder 7. The CD-ROM decoder 7 stores the decoded data from theCD decoder 5 to a buffer RAM 9 through a buffer manager 8. In addition,the CD-ROM decoder 7 conducts an error correcting process for thedecoded data stored in the buffer RAM 9, in order to obtain furtherreliability of the decoded data. In this case, the buffer manager 8handles to read the decoded data stored in the buffer RAM 9 and rewritethe decoded data on the buffer RAM 9.

The decoded data after the error correcting process is conducted by theCD-ROM decoder 7 is read out via the buffer manager 8 and then istransferred to a host computer HC externally connected to the opticaldisk apparatus 1. A host interface 10 interfaces between the externalhost computer HC and the optical disk apparatus 1 and for example, thehost interface 10 is based on standardization such as an ATAPI (ATattachment packet interface) or a SCSI (Small Computer SystemInterface).

On the other hand, in the optical disk 2 in which no data is recorded,ATIP data is embodied during a manufacturing stage. When data isrecorded in a blank area of the optical disk 2, the ATIP data is read bythe optical pickup 3. That is, a Wobble signal on the optical disk 2 isread by the optical pickup 3, amplified to be binary data by the readamplifier 4, and then output to the ATIP decoder 11 as ATIP data.

The ATIP decoder 11 decodes the ATIP data input from the read amplifier4 to generate a synchronizing signal (hereinafter, called ATIP SYNC) andtime information (hereinafter, called ATIP time information). Afterthat, the ATIP SYNC and the ATIP time information are output to a CDencoder 12. When data is written on the blank area of the optical disk2, the CD encoder 12 encodes the ATIP SYNC and the ATIP time informationthat is important information to detect a write location. Thus, it ispossible to write data from a precise location obtained based on theATIP SYNC and the ATIP time information from the CD encoder 12.

As described above, in the blank area of the optical disk 2, the ATIPtime information showing a blank area location of the optical disk 2 canbe obtain only from the ATIP data. On the contrary, in a recorded dataof the optical disk 2, since quality of the Wobble signal is lower, theATIP SYNC and the ATIP time information may not be precisely generatedby the ATIP decoder 11. However, in the recorded area of the opticaldisk 2, sub-code data is recorded as well as a sub-code SYND forsynchronization. The CD decoder 5 conducts a sub-code data process andoutputs the time information on the optical disk 2 to the CD encoder 12.When data is written on the recorded area of the optical disk 2, the CDencoder 12 obtains the time information showing the blank area locationof the optical disk using the sub-code data.

Data to be written on the optical disk 2 is transferred from the hostcomputer HC to the buffer RAM 9 via the buffer manager 8. The CD-ROMencoder 13 reads data from the buffer RAM 9 via the buffer manager 8 andadditionally provides an error correction code, an EDC code, SYNC code,header information, and a like to the data, and then rewrites on thebuffer RAM 9.

The CD-ROM encoder 13 reads the data from the buffer RAM 9 via thebuffer manager 8 and writes the data on a RAM 31 for a CIRC calculationin the CD encoder 12 (described later). The CD encoder 12 conducts aCIRC calculation for data in the RAM calculation, additionally providesthe error correction code, conducts an interleave operation, and furtherconducts the EFM modulation for the data to output. The data output fromthe CD encoder 12 is recorded on the optical disk 2 via a lasercontrolling circuit 14 and the optical pickup 3.

The Wobble signal obtained from the optical disk 2 is input to the servocircuit 15 via the optical pickup 3 and read amplifier 4 and a rotationcontrol signal generated by the servo circuit 15 is supplied to thespindle motor 17 via the motor driver 16. The CD decoder 5, the CD-ROMdecoder 7, the host interface 10, the ATIP decoder 11, the CD encoder12, the CD-ROM encoder 13 and the like are controlled by the CPU 20.

FIG. 2 is a diagram showing a format of a write-in unit for writing dataon a CD-R/RW, which is specified in an Orange Book. Generally, it is notpossible to successfully read data by writing the data on the user datablock because of a de-interleave operation when data recorded on theoptical disk 2 is reproduced and by a synchronizing operation. Thus, byproviding five blocks before the user data block and two redundantblocks after the user data block, the user data block is protected anddata can be successfully read.

The five blocks before the user data block includes a link block LB, a1st through a 4th run-in blocks RIB1 though RIB4. Two blocks after theuser data block includes a 1st run-out block ROB1 and a second run-outblock ROB2.

FIG. 3 is a diagram showing a format example of a case in which the userdata block shown in FIG. 2 is divided into several user data blocks whenrecorded on the optical disk 2.

Data is written in accordance with the format example shown in FIG. 3when the data from the host computer HC is received, and then the CDencoder 12 execute a start write StartW.

Moreover, the CD encoder 12 starts a write-in process for data to theoptical disk 2. When a data amount stored in the buffer RAM 9 isdecreased and then the buffer under run is likely to occur, the CDencoder 12 executes a pause write PW to temporarily stop writing data onthe optical disk 2. After that, the CD encoder 12 waits for a datatransmission from the host computer HC and executes a restart write ReWwhen the buffer RAM 9 accumulates data. The CD encoder 12 detects alocation where the write-in process for the data is temporarily stoppedby the pause write PW and then resumes the write-in process for the datafrom the location.

As described above, the CD encoder 12 repeats a process of temporarilystopping writing data by executing the pause write PW when the dataamount becomes smaller to be likely to cause the buffer under run andresuming writing data by the restart write ReW. When data from the hostcomputer HC is written on the optical disk 2, the CD encoder 12 executesa stop write StopW to complete the write-in process. By the write-inprocess controlled by the CD encoder 12, similar to the format shown inFIG. 2, the write-in process can be conducted as if only one singlewrite-in process is conducted.

A write-in control operation by each part shown in FIG. 1 will now bedescribed.

First, a CPU 20 issues a start write (StartW) instruction and the CDencoder 12 starts a write-in operation to the optical disk 2. Next, thebuffer manager 8 receives data transmitted from the host computer HC.The data is stored in the buffer RAM 9. The CPU 20 checks whether or notthe data amount of the buffer RAM 9 is decreased to a predeterminedlower data amount in accordance with a predetermined method.

When the data amount of the buffer RAM 9 is not decrease to thepredetermined lower data amount, the CPU 20 determines whether or not itis completed to write the data to the optical disk 2 in accordance witha predetermined firmware. When the CPU 20 determines that it iscompleted to write data, the CPU 20 issues a stop write (StopW)instruction to the CD encoder 12 and then the write-in process isterminated. On the other hand, it is not completed to write data, the CDencoder 12 continues to write data to the optical disk 2.

On the other hand, when the CPU 20 determines that the data amount ofthe buffer RAM 9 decreases to the predetermined lower data amount, theCPU 20 issues the pause write (PW) instruction to the CD encoder 12 andthen the write-in process to the optical disk 2 is interrupted. Next,the buffer manager 8 receives data transferred from the host computerHC, the data is stored in the buffer RAM 9, and the CPU 20 determineswhether or not the data amount of the buffer RAM 9 reaches apredetermined upper data amount in accordance with a predeterminedmethod.

When the CPU 20 determines that the data amount of the buffer RAM 9reaches the predetermined upper data amount, the CPU 20 issues therestart write (ReW) instruction to the CD encoder 12 so as to restartthe write-in process to the optical disk 2. The buffer manager 8receives data transferred from the host computer HC and stores in thebuffer RAM 9. On the other hand, when the CPU 20 determines that thedata amount of the buffer RAM 9 has not reached the predetermined upperdata amount, the buffer manager 8 continuously stores data transferredfrom the host computer HC and stores in the buffer RAM 9.

As described above, when the CPU 20 receives a write command from thehost computer HC and a certain data amount, the CPU 20 issues the startwrite (StartW) instruction for starting writing data. The start writeStartW instruction is a regular write sequence beginning from a linkblock and repeats to write data to the optical disk 2 and receive datafrom the host computer HC for a predetermined length. During thewrite-in process, in a case in which a data transmission speed from thehost computer HC is slower than a write-in speed to the optical disk 2,it becomes impossible to conduct the write-in process because of adecrease of the data amount in the buffer RAM 9.

Thus, the CPU 20 detects the decrease of the data amount in the bufferRAM 9 and determines that the data transmission is not sufficient, theCPU 20 issues the pause write (PW) instruction so as to interrupt thewrite-in process. In a case in which the write-in process is interruptedby the pause write (PW) instruction, a write sequence for interruptingthe write-in process without writing the run out block is used.

After that, when a sufficient data amount is received from the hostcomputer HC and data is stored in the buffer RAM 9, the CPU 20 issuesthe restart write (ReW) instruction. In a case of conducting thewrite-in process by the restart write (ReW), instead of writing data inthe link block like the regular write sequence, the write-in process isexecuted in accordance with a write sequence which is to preciselyconduct the write-in process from an end of data which is just writtenwhen the write-in process is interrupted, while maintaining a successivedata sequence from a write-in location where the write-in process isinterrupted and also maintaining synchronization even when the write-inlocation is positioned. When data is writen on the optical disk 2, theCPU 20 issues the stop write (StopW) instruction. When the write-inprocess is completed by the stop write (stopW) instruction, the regularwrite sequence is used to write the run out block.

As described above, the optical disk 1 monitors the data amount in thebuffer RAM 9 during the write sequence and repeats the pause write (PW)and the restart write (ReW) to prevent a write failure caused by thebuffer under run. Accordingly, when the data transmission is nosufficiently conducted to supply data to the buffer RAM 9 while writingdata on the optical disk 2, the write-in process is temporarilyinterrupted and the write-in process is restarted when a sufficient dataamount is transferred from the host computer HC. Therefore, even if thedata transmission from the host computer HC is temporarily interruptedor a data transfer rate becomes lower, data can be precisely written onthe optical disk 2 by dividing into multiple times. Consequently, it ispossible to prevent the write failure caused by the buffer under run.Moreover, the capacity of the buffer RAM 9 absorbing a data transferflow can be reduced, so that a cost of the optical disk apparatus 1 canbe reduced.

FIG. 4 is a schematic block diagram showing a configuration example ofthe CD encoder 12. In FIG. 4, a write-in operation conducted by the CDencoder 12 to the optical disk 2 will now be described.

Referring FIG. 4, the CD encoder 12 includes a clock signal generatingpart 30, a RAM 31 for a CIRC calculation, a CIRC calculating part 32, anEFM encoding part 33, and a write-in controlling part 34.

The clock signal generating part 30 generates a channel clock signalbeing a reference signal for writing data needed in the CD encoder 12,from a clock signal, for example, 33.8688 MHz, inputted from a crystaloscillator (not shown). Then, the clock signal generating part 30outputs the channel clock signal to each part provided in the CD encoder12. The RAM 31 for the CIRC calculation temporarily stores data to bewritten, which is read from the buffer RAM 9 by CD-ROM encoder 13, forthe CIRC calculation.

The CIRC calculating part 32 conducts the CIRC calculation for the datastored in the RAM 31 for the CIRC calculation, and further additionallyprovides an error correction code and conducts the interleave. The EFMencoding part 33 conducts the EFM modulation for the data processed bythe CIRC calculating part 32 in accordance with a predetermined methodand then outputs to the laser controlling circuit 14. In response to aninstruction from the CPU 20, the write-in controlling part 34 generatesa control signal for a write control for the CD interface part 35, whichinterfaces between the CD encoder 12 having the CIRC calculating part 32and the EFM encoding part 33, and the CD encoder 12. Also, the write-incontrolling part 34 outputs the control signal to the CD interface part35.

In detail, the write-in controlling part 34 generates a predeterminedwrite signal W when the start write (StartW) instruction is input fromthe CPU 20, generates a predetermined pause signal P when the pausewrite (PW) instruction is input from the CPU 20, and then outputs to theCIRC calculating part 32, the EFM encoding part 33, and the CD interfacepart 35. In addition, the write-in controlling part 34 generates apredetermined pause cancel signal PX when the restart write (ReW)instruction, generates a predetermined stop signal S when the step write(StopW) instruction is input from the CPU 20, and then outputs to theCIRC calculating part 32, the EFM encoding part 33, and the CD interfacepart 35. In FIG. 4, “A” denotes address data, “D” denotes data, “Req”denotes a request signal, and “Ack” denotes an acknowledge singal.

In this configuration, when the pause write (PW) instruction is outputfrom the CPU 20, the write-in controlling part 34 controls the CIRCcalculating part 32, the EFM encoding part 33, and the CD interface part35 to successively conduct the write-in process until a predeterminedEFM frame indicating an end of writing. When the write-in process isconducted until an end of the predetermined EFM frame, the CPU 20controls the CIRC calculating part 32, the EFM encoding part 33, and theCD interface part 35 to interrupt the write-in process. Also, the CIRCcalculating part 32, the EFM encoding part 33, and the CD interface part35, which all access the RAM 31 for the CIRC calculation, completes anycalculation and a read-out process required for the EFM frame at the endof the EFM frame. Accordingly, the CIRC calculating part 32, the EFMencoding part 33, and the CD interface part 35 are in a waiting state atrelative positions, as stopped at the end of the EFM frame.

In the waiting state, a generating operation for generation the addressdata, data request signal, and the acknowledge signal is stopped betweenthe CD encoder 12 having the CIRC calculating part 32 and the EFMencoding part 33, and the CD encoder 12. Also, the EFM encoding part 33cancels to output signals for writing such as the EFM signal, or a writegate signal WGATE. Since an output of the write gate signal WGATE iscancelled, it is interrupted to write data to the optical disk 2.

Since the CIRC calculating part 32 generating data to be writtenconducts the interleave, the same condition of data cannot be created,and a DSV (Digital Sum Value) calculation conducted by the EFM encodingpart 33 becomes irregular when the write-in operation is restarted, itis failed to write data to the optical disk 2 when the buffer under runoccurs. When the pause write (PW) instruction is received from the CPU20, each of the CD-ROM encoder 13, the CIRC calculating part 32, and theEFM encoding part 33, which access the RAM 31 for the CIRC calculationto generate data to be written, becomes in the waiting state at relativeposition as of a time when completing accessing the RAM 31 for the CIRCcalculation. Then, each of the CD-ROM encoder 13, the CIRC calculatingpart 32, and the EFM encoding part 33 is controlled to restart eachoperation simultaneously when the write-in operation is restarted, sothat the interleave can be managed. Simultaneously, the EFM encodingpart 33 is set in the waiting state. Accordingly, the DSV operation canbe prevented from being irregular.

In the waiting state (interruption state), when the restart write (ReW)instruction is output from the CPU 20, the write-in controlling part 34outputs the pause cancel signal PX to the CIRC calculating part 32, theEFM encoding part 33, and the CD interface part 35 after detecting alocation to restart to write as described later. As described above, theCIRC calculating part 32, the EFM encoding part 33, and the CD interfacepart 35 continue to process from the location of the waiting state, andthe EFM encoding part 33 restarts to output the EFM signal and the writegate signal WGATE. By restarting to output the EFM signal and the writegate signal WGATE, the write-in process to the optical disk 2 isrestarted from the position of the waiting state.

According to the embodiment, it is possible to conduct the write-inprocess while maintaining a continuity of data to be written at an endlocation of stopping to write data to the optical disk 2 and at arestart location of restarting to write data. Therefore, it is possibleto precisely and successively read out data even after the data writeoperation is temporarily stopped during the write-in process and thenthe data write operation is restarted.

FIG. 5 is a flowchart for explaining the write control operation exampleconducted in the optical disk apparatus 1 shown in FIG. 1 and FIG. 4.

In FIG. 5, the CPU 20 issues the start write (StartW) instruction to thewrite-in controlling part 34 (step ST1). The write-in controlling part34 outputs the write signal W to the CIRC calculating part 32, the EFMencoding part 33, and the CD interface part 35, and then the data writeoperation to the optical disk 2 is started (step ST2). Subsequently, thebuffer manager 8 receives data transferred from the host computer HC andstores the data in the buffer RAM 9 (step ST3). The CPU 20 checkswhether or not the data amount in the buffer RAM 9 is decreased to thepredetermined lower data amount in accordance with a predeterminedmethod (step ST4).

When the data amount is not decreased to the predetermined lower dataamount (NO) in step ST4, the CPU 20 determines whether or not the datawrite operation to the optical disk 2 is completed, in accordance with apredetermined firmware (step ST5). When the data write operation iscompleted (YES) in step ST5, the CPU 20 issues the stop write (StopW)instruction to the write-in controlling part 34 (step ST6). The write-incontrolling part 34 outputs the predetermined stop signal S to the CIRCcalculating part 32, the EFM encoding part 33, and the CD interface part35, so as to complete the data write operation to the optical disk 2(step ST7). Then, the write control operation is terminated. On theother hand, in step ST5, when the data write operation is completed(NO), the write control operation goes back to step ST2.

On the other hand, in step ST4, when it is determined that the dataamount in the buffer RAM 9 is decreased to the predetermined lower dataamount (YES), the CPU 20 issues the pause write (PW) instruction to thewrite-in controlling part 34 (step ST8). The write-in controlling part34 outputs the CIRC calculating part 32, the EFM encoding part 33, andthe CD interface part 35, so as to interrupt the data write operation tothe optical disk 2 (step ST9). Subsequently, the buffer manager 8receives data transferred from the host computer HC, and stores the datato the buffer RAM 9 (step ST10). The CPU 20 checks whether or not thedata amount in the buffer RAM 9 fills up the buffer RAM 9, that is, thedata amount of the buffer RAM 9 reaches the predetermined upper dataamount (step ST11).

When it is determined in step ST11 that the data amount reaches thepredetermined upper data amount (YES), the CPU 20 issues the restartwrite (ReW) instruction to the write-in controlling part 34 (step ST12).The write-in controlling part 34 outputs the predetermined pause cancelsignal PX to the CIRC calculating part 32, the EFM encoding part 33, andthe CD interface part 35, and then the data write operation to theoptical disk 2 is restarted (step ST13). The write control operationgoes back to the step ST10 so as to continue the write-in process.

Next, a process for detecting a restart write location will now bedescribed.

FIG. 6 is a diagram showing a relationship between an end locationindicating an end writing data and a start location indicating a startwriting data on the optical disk 2, which is specified by the OrangeBook. Referring to FIG. 6, four EFM frames, which is considerably largedata amount, are allowed to overlap in the Red Book. Such a large dataamount causes a frame synchronization shift even in the optical diskapparatus 1 used for a CD having higher correction ability and then anormal reproduction cannot be conducted. Such the considerably largedata amount is allowed to absorb a rotation control error of the spindlemotor 17. That is, a next start write location is determined based onthe ATIP SYNC demodulated from the Wobble signal, regardless of datathat has written.

In order to reproduce data without losing synchronization at aconnection location of recording data, a format shown in FIG. 7 is usedconsidering a window width for a frame synchronization protection. Thatis, in order to write data for a reproduction without losingsynchronization, it is required to form the connection location ofrecording data within a shift of approximately ±2 bit clocks. A write-incontrol based on an accuracy of the rotation control by the spindlemotor in the conventional optical disk apparatus cannot preciselydetermine a data write-in location as the connection location.

In the optical disk apparatus 1 according to the embodiment of thepresent invention, when the pause write (PW) instruction is issued bythe CPU 20, the write-in control part 34 stores information, whichindicates until which EFM frame data is written, on a basis of the timeinformation on that time and the sub-code SYNC (S0 or S1), to aninternal register (not shown). The write-in control part 34 writes datauntil an end of the EFM frame indicated by the information andinterrupts the write-in process. In a rewrite-in process by the CPU 20outputting the restart write (ReW) instruction, the CPU 20 reads out andconfirms the connection location on the optical disks 2 where thewrite-in process is interrupted, and then seeks to position just beforethe connection location.

After the CPU 20 seeks, the write-in controlling part 34 advances fromthe ATIP time information or the time information to a time ofinterrupting to write data, waits for the sub-code SYNC (S0 or S1).Then, the write-in controlling part 34 waits for a frame SYNC for thenumber of the EFM frames, when the write-in controlling part 34 detectsthe sub-code SYNC. The write-in controlling part 34 always interrupts towrite data at a position of writing the frame SYNC in a case ofinterrupting to write data. Then, the write-in controlling part 34restarts to write data after waiting for a demodulation delay time ofthe frame SYNC from a time when it is interrupted to write data. Thus,it is possible to precisely joint data on the optical disk 2.

FIG. 8 is a diagram showing a relationship between the sub-code SYNC andthe frame SYNC on the optical disk 2 and the sub-code SYNC and the frameSYNC after demodulated. The sub-code SYNC and the frame SYNC shown inFIG. 8 can be obtained even in a case a general-purpose LSI, which isspecially used for a CD decode function and cheaper, is used. As can beseen from FIG. 8, a peculiar demodulation delay occurs when the sub-codeSYNC and the frame SYNC are demodulated. In order to precisely jointdata on the optical disk 2 in a case of restarting to write data, it isrequired to correct the peculiar demodulation delay. By allowing thewrite-in controlling part 34 to set a correction amount, it is possibleto correct the peculiar demodulation delay, regardless of differencesbetween optical pickups or decoders of various optical apparatuses.

On the other hand, in a case of writing data to the optical disk 2, inorder to check whether or not to complete to normally write data, apseudo-write-in process (hereinafter, called test write process) isconducted to check a series of the data write operation without actuallyconducting the write-in process. In this case, when an interruption anda restart write process is conducted because of occurrence of the bufferunder run similarly to the write-in process actually conducted,differently from the write-in control operation, data recorded on theoptical disk 2 cannot be detected since the write-in process is notactually conducted. Consequently, the restart write process cannot bestarted. In this case, by starting to write by a timing of the Wobblesignal on the optical disk 2 such as a CD-R/RW, a DVD−R/RW, or a DVD+RW,it is possible to normally restart to write data even in the case inwhich no data is written on the optical disk 2.

FIG. 9 is a diagram showing a relationship of the ATIP SYNC afterdemodulated. As can be seen from FIG. 9, the peculiar demodulation delayoccurs even in a case of corresponding to the restart write locationusing the ATIP SYNC when the test write process. When the restart writeprocess is conducted, it is required to correct the peculiardemodulation delay in order to precisely joint data on the optical disk2. By allowing the write-in controlling part 34 to arbitrarily set thecorrection amount, it is possible to precisely restart to write data,regardless of differences between optical pickups or decoders of variousoptical apparatuses.

Also, as shown in FIG. 10, in a case in which end data showing an end ofwritten data and data to restart to write are formed by pits, a space isformed because an error of corresponding to the restart write locationis caused when the restart write process is conducted. The space isirregular, that is, a state in which no pit formed is caused. Since aPLL (Phase Locked Loop) (not shown) for reading data in the CD decoder 5is controlled by a specified minimum pit, a specified maximum pit, or aspecified space length, the PLL may irregularly operate if the spacelength that is not specified is formed on the optical disk 2. Thus,spaces are defined as the end data written-in and the data to restart towrite-in, so that it is possible to avoid problems described above evenif the space is formed at the connection location.

Moreover, two types of EFM data actually recorded on the optical disk 2are generated from an EFM code as shown in FIG. 11. When a margin bitbegins from a space and the SYNC code begins from a bit, data is jointedat the margin bit. When a regular length of the margin bit, which is 3T(“T” denotes one cycle of the clock signal CK) in FIG. 11, becomes morethan 3T because of a rotation change of the spindle motor 17 or thesynchronization shift, it is possible to normally read data when a SYNCpattern is recognized by the synchronization protection in the CDdecoder 5. That is, it is possible to successfully read data without anerror for the sub-code data and main data. It should be noted that theclock signal CK in FIG. 10 and FIG. 11 indicates the channel clocksignal.

Generally, the decoder 5 conducts the synchronization protection for aSYNC part and the error correction for a data part considering a readingerror when data is read. It is preferable to define the connectionlocation at the SYNC part for conducting the synchronization protection.Moreover, since a function of jointing data at a space of the SYNCpattern is provided as described above, an error caused by correspondingthe restart location can be eliminated by using the synchronizationprotection of the CD decoder 5.

As describe above, a case of writing data to the optical disk 2 by a CLVcontrol is exampled. Problems of defining the space at the connectionlocation of data and handling the connection location are caused byconducting the CLV control. In the CLV control, the rotation controlerror of the spindle motor 17 is caused by conducting the rotationcontrol synchronizing with a clock in a write system and also, a phasedifference is caused between clocks of a read system and the writesystem. As a result, a location correspondence error occurs at theconnection location of data on the optical disk 2. Even if a rotationchange of the optical disk 2, which is caused by the phase error betweenthe clocks of the read system and the write system, is minimized, asampling error occurs.

On the contrary, in a CAV control (Constant Angular Velocity) forcontrolling to lock the PLL to the Wobble signal read from the opticaldisk by corresponding to a rotation number of the optical disk 2, theend location and the restart location can be synchronized with theWobble signal. Thus, it is possible to minimize the locationcorrespondence error caused by jointing data at the connection locationmore than the CLV control. In addition, in the CAV control, since amovement of the spindle motor 17 is synchronized with the clock of thewrite system, the rotation change of the optical disk 2 can be ignored.Accordingly, the read system and the write system are synchronized.Thus, it is possible to suppress an occurrence of the sampling error.

Furthermore, in a case of conducting the CAV control, in the clocksignal generating part 30 in FIG. 4, instead of inputting the clocksignal of 33.8688 MHz from the crystal oscillator (not shown), theWobble signal, which is a binary and input via the ATIP decoder 11. Theclock signal generating part 30 generates the channel clock signal basedon the Wobble signal and inputs to each part of the CD encoder 12.

As described above, in the optical disk apparatus 1 according to theembodiment of the present invention, when the pause write PW is issued,the write-in controlling part 34 stores the time information at thattime and information indicating how many EFM frames are used for writingdata based on the sub-code SYNC to be written, to the internal register.The write-in controlling part 34 interrupts the write-in process afterwriting data until the end of the EFM frame. And the write-incontrolling part 34 advances to the time of interrupting to write databased on the ATIP time information and the time information of thesub-code when the restart write (ReW) instruction is issued, and waitsfor the sub-code SYNC. When the write-in controlling part 34 detects thesub-code SYNC, the write-in controlling part 34 restarts to write datafrom the restart location by counting the sub-code SYNC as a frame SYNCfor the number of the EFM frames. Therefore, data can be preciselyjointed on the optical disk 2 when the restart write ReW is executed. Inaddition, the write-in process is interrupted when the buffer under runis caused. And when the write-in process is restarted, the write-inprocess is conducted as if data has been successively written on theoptical disk 2.

As can be seen from the above explanation, in an optical disk apparatuswhere the present invention is applied, such as the optical diskapparatus 1, when the write-in process to the optical disk isinterrupted, a data processing part and a encoder part are set to be inthe waiting state after an access to a data storing part is completed,so as to stop to access the data storing part and also to stop to storedata to write. Thus, the interleave can be managed and the DSVcalculation can be properly conducted without any irregular calculation.Even in a case the write-in process to the optical disk is restartedafter temporarily interrupted, it is possible to read data similar to acase in which data to be written is successively written without aninterruption.

Moreover, an end location information storing part is provided to storeend location information showing an end write location where it ends towrite data on the optical disk. When it ends to write data on theoptical disk, end location information of a location on the optical diskis stored in the end location information storing part. Accordingly, itis possible to easily check a seek location and a start write locationwhen the restart write process is conducted.

In detail, the end write location is detected based on a locationinformation obtained from data recorded the optical disk, from the endlocation storing part. When data recorded on the optical disk is read,based on each format of the CD-R/RW, the DVD−R/RW, and the DVD+R, atiming signal showing one sector or one frame is extracted. By using thetiming signal, it is possible to synchronize with data being written onthe optical disk, and it is possible to restart to write data justbefore the end write location.

Furthermore, in order to check whether or not to normally write datawhen data is written on the optical disk, instead of actually conductingthe data write operation, there is the test write as a pseudo-write-inprocess to check a series of the data write operation. In this case,when an interruption and a restart write process is conducted because ofoccurrence of the buffer under run similarly to the write-in processactually conducted, differently from the write-in control operation,data recorded on the optical disk cannot be detected since the write-inprocess is not actually conducted. Consequently, the restart writeprocess cannot be started. In this case, by starting to write by atiming of the Wobble signal on the optical disk such as a CD-R/RW, aDVD−R/RW, or a DVD+RW, it is possible to normally restart to write dataeven in the case in which no data is written on the optical disk.

Moreover, when the Wobble signal formed on the optical disk isdemodulated, the peculiar demodulation delay is occurred. In order toprecisely joint data on the optical disk when the restart write processis conducted, it is required to correct the demodulation delay. Thus,the correction amount is arbitrarily defined, so as to correct thedemodulation delay, regardless of differences between optical pickups ordecoders of various optical apparatuses.

In detail, when data is written from the end write location, a writeoperation instructing part can determine a restart write location and aseek location for restarting to write data by using the end locationinformation stored in the end location information storing part.

Alternatively, a current location on the optical disk and end locationinformation stored in the end location information storing part may becompared. When the current location corresponds to the end locationinformation, a restart write operation may be automatically conducted.Thus, it is possible to reduce workload in the write operationinstructing part used by a CPU or a like.

Also, because the end write location is not detected when the end writelocation stored in the end location information storing part isdetected, if a seek operation is conducted again due to a retry ofwriting data when the restart write operation is not properly started,an irregular end write location is detected and the restart writeoperation is started while being unstable reading condition. Accordingto the present invention, when the restart write operation is retired,the end write location is detected when a reading condition becomesstable after the retry of seeking the optical disk. Therefore, it ispossible to prevent the restart write operation from being started inthe unstable reading condition.

On the other hand, in a case in which end data showing an end of writtendata and data to restart to write are formed by pits, a space is formedbecause an error of corresponding to the restart write location iscaused when the restart write process is conducted. Since a PLL (PhaseLocked Loop) (not shown) for reading data is controlled by a specifiedminimum pit, a specified maximum pit, or a specified space length, thePLL may irregularly operate if the space length that is not specified isformed on the optical disk. Thus, spaces are defined as the end datawritten-in and the data to restart to write-in, so that it is possibleto avoid problems described above even if the space is formed at theconnection location.

In detail, by defining the connection location of data as a space of theEFM frame SYNC, an error caused by corresponding the restart locationcan be eliminated by using the synchronization protection conducted whenread data is demodulated. Therefore, it is possible to conduct a datawrite operation so as to precisely reproduce data recorded on theoptical disk.

Furthermore, according to the present invention, the CAV control(Constant Angular Velocity) for controlling to lock the PLL to theWobble signal read from the optical disk, is conducted by correspondingto a rotation number of the optical disk. The end location and therestart location can be synchronized with the Wobble signal. Thus, it ispossible to further minimize an error of the connection location of datamore than the CLV control.

The present invention is not limited to the specifically disclosedembodiments, and variations and modifications may be made withoutdeparting from the scope of the present invention.

The present application is based on the Japanese priority applicationsNo.2000-332409 filed on Oct. 31, 2000, entire contents of which arehereby incorporated by reference.

1. An optical disk apparatus for recording and reproducing informationto an optical disk, said optical disk apparatus comprising: a datastoring part temporarily storing data externally transferred to bewritten on said optical disk; a data processing part for conducting apredetermined data process for said data stored in said data storingpart; an encoding part modulating and outputting said data processed bysaid data processing part; a write-in controlling part conducting anoperation control of said data processing part and said encoding part,and conducting a storing control for storing said data to be written tosaid storing part; and a write-in operation instruction part detecting astate of interrupting supplying said data to be written to said datastoring part, and sending an operation instruction to said write-incontrolling part in accordance with a detection result; wherein whensaid write-in controlling part interrupts writing of data to the opticaldisk, said write-in controlling part sets said data processing part andsaid encoding part in a waiting state after an access to said datastoring part is completed, so that the access to said data storing partis stopped, to allow said data to be written to accumulate in said datastoring part, and wherein said write-in controlling part detectsinformation showing an end write location based on absolute locationinformation showing an absolute location of a blank area that is formedon the optical disk beforehand.
 2. The optical disk apparatus as claimedin claim 1, further comprising an end location information part storingend location information showing an end write location where writingdata is ended on said optical disk.
 3. The optical disk apparatus asclaimed in claim 2, wherein said write-in controlling part detects theend write location based on said information showing the end writelocation stored in said end location information storing part anddetermined based on said location information obtained from datarecorded on said optical disk.
 4. The optical apparatus as claimed inclaim 3, wherein said write-in controlling part conducts a correctionfor a delay time caused when said location information read and obtainedfrom said optical disk is demodulated, by using a predeterminedcorrection amount.
 5. The optical disk apparatus as claimed in claim 1,wherein said write-in controlling part defines a space between an endwrite location and a restart write location.
 6. The optical diskapparatus as claimed in claim 5, wherein: said encoding part conducts anEFM modulation for said data processed by said data processing part tobe written in accordance with a predetermined method, and outputs amodulation result; and said write-in controlling part defines a space ofan EFM frame synchronization as said end location and defines said spaceas a start location to start, and starts to write data from said space.7. An optical disk apparatus for recording and reproducing informationto an optical disk, said optical disk apparatus comprising: a datastoring part temporarily storing data externally transferred to bewritten on said optical disk; a data processing part for conducting apredetermined data process for said data stored in said data storingpart; an encoding part modulating and outputting said data processed bysaid data processing part; a write-in controlling part conducting anoperation control of said data processing part and said encoding part,and conducting a storing control for storing said data to be written tosaid storing part; and a write-in operation instruction part detecting astate of interrupting supplying said data to be written to said datastoring part, and sending an operation instruction to said write-incontrolling part in accordance with a detection result, an end locationinformation part storing end location information showing an end writelocation where writing data is ended on said optical disk, wherein whensaid write-in controlling part interrupts writing of data to the opticaldisk, said write-in controlling part sets said data processing part andsaid encoding part in a waiting state after an access to said datastoring part is completed, so that the access to said data storing partis stopped, to allow said data to be written to accumulate in said datastoring part, and wherein said write-in controlling part detects saidinformation showing the end write location stored in said end locationinformation storing part based on absolute location information showingan absolute location of a blank area that is formed on the optical diskbeforehand.
 8. An optical disk apparatus for recording and reproducinginformation to an optical disk, said optical disk apparatus comprising:a data storing part temporarily storing data externally transferred tobe written on said optical disk; a data processing part for conducting apredetermined data process for said data stored in said data storingpart; an encoding part modulating and outputting said data processed bysaid data processing part; a write-in controlling part conducting anoperation control of said data processing part and said encoding part,and conducting a storing control for storing said data to be written tosaid storing part; and a write-in operation instruction part detecting astate of interrupting supplying said data to be written to said datastoring part, and sending an operation instruction to said write-incontrolling part in accordance with a detection result, wherein whensaid write-in controlling part interrupts writing of data to the opticaldisk, said write-in controlling part sets said data processing part andsaid encoding part in a waiting state after an access to said datastoring part is completed, so that the access to said data storing partis stopped, to allow said data to be written to accumulate in said datastoring part, wherein said write-in controlling part detects the endwrite location based on said information showing the end write locationstored in said end location information storing part and determinedbased on said location information obtained from data recorded on saidoptical disk, and wherein when data is written from said end writelocation, said write-in operation instructing part detects said endwrite location based on said end location information stored in said endlocation information storing part, after seeking an optical pickupreading and writing data to said optical disk from said end location toa location just before a predetermined location based on said endlocation information stored in said end location information storingpart.
 9. An optical disk apparatus for recording and reproducinginformation to an optical disk, said optical disk apparatus comprising:a data storing part temporarily storing data externally transferred tobe written on said optical disk; a data processing part for conducting apredetermined data process for said data stored in said data storingpart; an encoding part modulating and outputting said data processed bysaid data processing part; a write-in controlling part conducting anoperation control of said data processing part and said encoding part,and conducting a storing control for storing said data to be written tosaid storing part; and a write-in operation instruction part detecting astate of interrupting supplying said data to be written to said datastoring part, and sending an operation instruction to said write-incontrolling part in accordance with a detection result, wherein whensaid write-in controlling part interrupts writing of data to the opticaldisk, said write-in controlling part sets said data processing part andsaid encoding part in a waiting state after an access to said datastoring part is completed, so that the access to said data storing partis stopped, to allow said data to be written to accumulate in said datastoring part, wherein said write-in controlling part detects the endwrite location based on said information showing the end write locationstored in said end location information storing part and determinedbased on said location information obtained from data recorded on saidoptical disk, and wherein when data is written from said end location,said write-in controlling part detects said end write location based onsaid end location information stored in said end location informationstoring part, after seeking an optical pickup reading and writing datato said optical disk from said end location to a location just before apredetermined location based on said end location information stored insaid end location information storing part.
 10. The optical diskapparatus as claimed in claim 9, wherein when data is written from saidend write location and when writing data is not started from said endwrite location, after a restart write operation to the optical disk isinterrupted and said write-in controlling part controls said opticalpickup to seek from said end location to said location just before saidpredetermined location based on said end location information stored insaid end location information storing part again, said write-incontrolling part detects said end write location based on said endlocation information stored in said end location information storingpart.
 11. An optical disk apparatus for recording and reproducinginformation to an optical disk, said optical disk apparatus comprising:a data storing part temporarily storing data externally transferred tobe written on said optical disk; a data processing part for conducting apredetermined data process for said data stored in said data storingpart; an encoding part modulating and outputting said data processed bysaid data processing part; a write-in controlling part conducting anoperation control of said data processing part and said encoding part,and conducting a storing control for storing said data to be written tosaid storing part; a write-in operation instruction part detecting astate of interrupting supplying said data to be written to said datastoring part, and sending an operation instruction to said write-incontrolling part in accordance with a detection result; and a clocksignal generating part including a Phase Locked Loop circuit forgenerating a reference clock signal for writing data by corresponding toa rotation number of said optical disk so as to lock to a Wobble signalread from said optical disk in order to conduct a Constant AngularVelocity control, wherein the reference clock signal is used to obtain adata write-in timing when data is recorded on said optical disk; andwherein when said write-in controlling part interrupts writing of datato the optical disk, said write-in controlling part sets said dataprocessing part and said encoding part in a waiting state after anaccess to said data storing part is completed, so that the access tosaid data storing part is stopped, to allow said data to be written toaccumulate in said data storing part.